Such a valve control apparatus is for example known from DE 42 32 205 C2. The apparatus can be used in particular as a control apparatus for an anti-blocking system (ABS) in a motor vehicle in which the brake fluid that actuates the wheel brakes is controlled with two valves per wheel. The valves are each actuated by an electromagnet.
The ABS system known from the above-cited letters patent comprises a housing having a housing frame and a cover. In the interior of the housing a circuit bearer is arranged that is fastened on an aluminum base plate, e.g. by gluing. The housing frame comprises two plug parts manufactured together with it, of which the first is oriented perpendicular to a lateral surface and the second is oriented obliquely to the lower main surface of the housing frame. The plug pins, given by additional mechanical individual parts, are connected electrically with the circuit bearer in the assembly of the valve control apparatus, just as are the terminal wires of the valve coils, in that the plug pins and the terminal wires are plugged and soldered through bores of the circuit bearer.
The construction of the known apparatus is expensive, due to the complex spatial interplay of many different individual components (circuit boards, plug parts, plug pins, electronic components, valve coils) and due to the soldering processes. Due to its limitation to one plane, a conventional circuit bearer, e.g. a circuit board, is fundamentally not optimally suited for the essentially three-dimensional design of an ABS module. The use of a pressed screen (leadframe) made three-dimensional by corresponding shaping and subsequent bending leads no further, because from the manufacturing point of view this screen can be manufactured only at great expense.
On the other hand, today MIDs (Molded Interconnect Devices), i.e. three-dimensional circuit boards, provide a new technology with greater constructive freedom, especially spatially. A compound element is thereby produced from various plastics, mainly using two-shot injection-molding technique, of which one of the plastics must be metallizable and the other not. The switching layout is accordingly produced by means of the shaping of the injection-molding dies in such a way that the compound element receives a surface that can be selectively metallized (by means of etching and galvanization). However, this manufacturing technology also requires relatively high die costs, so that in general a reduced expense for the module to be produced results only if the number of components is actually considerably reduced. Above all, this is possible only with difficulty if components bound locally in the apparatus, here the valve coils and plug parts, are present that must also be located in the same place in the new solution in MID technology.
Therefore, there is a need for a valve control apparatus of the type named above that can be produced less expensively.